We’ve been talking with sources in the know, and from the information we’ve been given, it is very unlikely that the X Phone would be sold as a customizable device. Those close to the X Phone project said that the most likely to know about this have never heard about the plan. And, if they haven't heard, its highly unlikely to happen.
However, that’s not to say that Guy Kawasaki is not to be believed. The X Phone may not offer customization, but we’ve been told that it is a real possibility to see a Motorola device that is customizable later in the year. This makes sense because, we’ve already seen Google managing expectations about the X Phone, which would seem to indicate that the real Googley options aren’t coming with the X Phone.